AN6884 - VU Led Level meter for amplifiers


AN6884 - VU Led Level meter for amplifiers

AN6884 - VU Led Level meter for amplifiers circuit The basic component is the complete AN6884 by Panasonic. The AN6884 is a monolithic integrated circuit driving 5- LED and is capable of logarithmic (dB) bar graph display for input signal. Incorporating high gain rectification amp. Enable to apply AC (VU meter, etc.) / DC (signal meter, etc.) Level meter widely. The system operates...

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2x15w stereo power amplifier circuits based TDA1521

It is small and compact stereo amplifier is powerful but can easily be used to replace your broken amplifier or new construction, or to make an active speaker, in all cases combined with a preamplifier. With remarkable features make it the true Hi-Fi amplifier.
Using only active component (the right and left channel) Philips TDA1521 monolithic integrated circuit, which contains a double line-end audio amplifier completely independent, each capable of providing from 10 to 12 W to the load 8 ohm or 15 W into 4 ohms (30 W music). Voltage gains of the amplifier is fixed at 30 dB.
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CLASS AB BJT 100W Hi-End AUDIO AMPLIFIER CIRCUITS

Symasym5, is a "cute" power amplifier, designed with quality but still low price in mind. This resulted in a ClassAB BJT amplifier, using only TO92 transistors for input and VAS, with a reasonable part count. The topology used is well known and consist of a single diffamp for input, plus a 2nd diffamp with current mirror for VAS. This is followed by normal darlington EF outputstage using modern high beta devices. The circuit uses large amounts of feedback over the whole audioband and an unconventional feedback compensation scheme. Right now symasym is designed to be driven directly from a CD/DVD-player, simply place a 22k poslog stereo pot between player and symasym. (as voltage divider)
Update
The at least change is to reduce C14 from 22pF to 10pF, but i recommend to follow Pavel's advice.
I recommend C14 with 10pF also for MJLs, this increases safety margin.
Do not forget to read Pavel's Review! A very promising evaluation of the qualities to be expected from symasym. Thanks Pavel !
Another update are the resistors R31/32 to be increased from 22ohm to 47ohm. Symasym5_3 is an update of v5.2, with an improved board layout concerning power gnd,
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